Nutrient´s ratio - of importance or not?

[Lasse]

Let me crush this P04 myth right here.

Where does P04 come from in the ocean? Anybody? Raise your hand. Dont be shy.
The main source of P04 is from agriculture and industry. If it wasnt for farm runoffs P04 would even be rarer in the open ocean as it is now. Anybody want to argue that point puts them at odds with every marine and environmental biologist on the planet.

So, what we are saying is the corals in the ocean have only existed for a hundred years or so because prior to that P04 didn't exist in levels like it does now because industrial fertilizers werent in use. That's pretty stupid.

Phosphate acts like methamphetamine in corals. It hyper stimulates symbiotic algae in corals and causes them to starve the coral tissue of nutrients.

A decade ago reefers targeted zero nitrate and phosphate. Now we are trying to balance nutrients on the head of a pin because we dont want to reduce our bioload and yet want to add calcium to tanks that arent consuming it.

My best growing SPS tanks test zero for phosphate and show a trace of nitrate or less. Softies like this junk ....SPS doesnt.

This is total nonsense - the major part of the phosphorous in the oceans are still coming from the depths where degraded organic matter release phosphorus into the sediments and into the water. It will be transported up to the upper layer of the oceans ( 0 - 200 m) where the sunlight initiate phytoplankton blooms or its going into coral reefs and promote both algae and coral growths. Even if the corals is not photosynthetic - they are eating phytoplankton and zoo plankton produced of the upwelling phosphorus. Just Google upwelling. The aera there I live - around the North Sea is known for its very high production of fish and the base of this - long, long, long, long before 1913 and the start of the industrial production of ammonia accompanying of the need for industrial utilization of mineralized phosphorus. The reason for the high production is the currents transporting among other things upwelled phosphorous (I hope you do not mean that the high fish production in the north sea started after 1918)

Next question - where does the nitrogen in the ocean coming from? It can´t be stored as mineralized matter. Most of the nitrogen circulation in the seas comes from - cyanobacteria.

In some places (like the Baltic Sea) and part of the Mexican Gulf - humans had succeeded to create an eutrophication in the seas - but that´s a total other thing - not yet valid even for the mediterranean parts of the world. The phosphorus concentrations around 0.04 ppm have been in the oceans for million of years - of course we will sooner or later impact on the concentrations of phosphorus in the open sea as we have done with the CO2 - but we are not there yet. The primary production is also so fast and heavy depended of phosphorous (if nitrogen not is limited) that it have been showed that with higher temperatures, more available nitrogen you will get bleaching events because of phosphorous starvation.

It have also been shown that coral reefs close to islands with a high sea bird population have a higher production of fish and other sea creature compared with island nearby there the bird population is greatly reduced due to rats' predation of their eggs. (guano leakage during rainfall)

Sincerely Lasse

 

[X-37B]

Since my last post 4 months ago I have p04 .02 max no3 <2.
Feeding 2 cube amounts 4 times a day.
No cyano seen.
I have good coral growth.
Had alot of coralline on back wall but urchins are keeping it thinned out.
I am at the point now, 1 year since startup, that I have to frag some corals to control direction of growth.

I have for the last 10 months been running 3 liters of eheim substrate pro in a mesh bag in the sump.
No3 has rarely been over 2 in my system.
It may help keep no3 down.
I shake it maybe every 2 months at best.

The only time I have seen cyano is in the first month of startup.
It was .2 and was from caribsea dry rock that was 50/50 with live.
I brought it down with phosgaurd and it has been stable since.

I have been told by lfs and local reefers that I need to raise both.

Think I will keep the numbers I have, lol.

 

[Hans-Werner]

It can´t be stored as mineralized matter. Most of the nitrogen circulation in the seas comes from - cyanobacteria.

Yes, but the situation is a bit different. Nitrogen compounds can be oxidized to nitrate. This nitrate-N usually is called recycled N while organic and NH4-N is called new N, meaning new from N2-fixation. In upwelling regions nitrate may be high, in reefs usually most N is new N, depending from the contribution of upwelling, for example at islands, and N2 fixation.

 

[TanksJB]

This is total nonsense - the major part of the phosphorous in the oceans are still coming from the depths where degraded organic matter release phosphorus into the sediments and into the water. It will be transported up to the upper layer of the oceans ( 0 - 200 m) where the sunlight initiate phytoplankton blooms or its going into coral reefs and promote both algae and coral growths. Even if the corals is not photosynthetic - they are eating phytoplankton and zoo plankton produced of the upwelling phosphorus. Just Google upwelling. The aera there I live - around the North Sea is known for its very high production of fish and the base of this - long, long, long, long before 1913 and the start of the industrial production of ammonia accompanying of the need for industrial utilization of mineralized phosphorus. The reason for the high production is the currents transporting among other things upwelled phosphorous (I hope you do not mean that the high fish production in the north sea started after 1918)

Next question - where does the nitrogen in the ocean coming from? It can´t be stored as mineralized matter. Most of the nitrogen circulation in the seas comes from - cyanobacteria.

In some places (like the Baltic Sea) and part of the Mexican Gulf - humans had succeeded to create an eutrophication in the seas - but that´s a total other thing - not yet valid even for the mediterranean parts of the world. The phosphorus concentrations around 0.04 ppm have been in the oceans for million of years - of course we will sooner or later impact on the concentrations of phosphorus in the open sea as we have done with the CO2 - but we are not there yet. The primary production is also so fast and heavy depended of phosphorous (if nitrogen not is limited) that it have been showed that with higher temperatures, more available nitrogen you will get bleaching events because of phosphorous starvation.

It have also been shown that coral reefs close to islands with a high sea bird population have a higher production of fish and other sea creature compared with island nearby there the bird population is greatly reduced due to rats' predation of their eggs. (guano leakage during rainfall)

Sincerely Lasse

Regarding NO3O4 ratio.
Lasse, I would like your thoughts and others on this ratio. I am getting wildly different answers which leads me to believe perhaps the ratio is not as important as some think. I am not a chemist so I need help on this. I am interested in what I get on the standard tests from Hanna (Phosphate) and ATI lab in Europe (https://lab.atiaquaristik.com).
Ryun on the BRS video says 10:1
BRS help desk said "We typically aim for 5-10 ppm nitrate, and 0.04ppm phosphate", which is about 16:1 or so.
The makers of PaxBellum, a nitrate supplement sold by BRS, says anywhere between 20:1 and 200:1, with 100:1 as ideal.
Thanks in advance for any advice on this.

 

[TanksJB]

The happy face was an accident. NO3O4

 

[TanksJB]

Did it again, sorry, but you know I guess what I am trying to post

 

[TanksJB]

The 16:1 for the help desk should be 160:1 I think.

 

[Dan_P]

Regarding NO3O4 ratio.
Lasse, I would like your thoughts and others on this ratio. I am getting wildly different answers which leads me to believe perhaps the ratio is not as important as some think. I am not a chemist so I need help on this. I am interested in what I get on the standard tests from Hanna (Phosphate) and ATI lab in Europe (https://lab.atiaquaristik.com).
Ryun on the BRS video says 10:1
BRS help desk said "We typically aim for 5-10 ppm nitrate, and 0.04ppm phosphate", which is about 16:1 or so.
The makers of PaxBellum, a nitrate supplement sold by BRS, says anywhere between 20:1 and 200:1, with 100:1 as ideal.
Thanks in advance for any advice on this.

The ratio of nutrients in an aquarium is probably a useless concept. The concentration of nitrate and phosphate seem important. Aquarists find undetectable PO4 bad for coral growth. At the high end some coral but not all can suffer around 0.1 ppm. So, the current consensus in the hobby is to use 0 and 0.1 ppm as guardrails for maintaining PO4 level. 0ppm nitrate may also be harmful to coral as would the high end. It seems that the hobby guardrails are 0 and 10 or 25 ppm. Drive your numbers between these guardrails. Their is no scientific evidence that there is a special ratio of nutrients. No ”sweet spots” that make corals grow rapidly.

 

[Randy Holmes-Farley]

Regarding NO3O4 ratio.

Lasse, I would like your thoughts and others on this ratio. I am getting wildly different answers which leads me to believe perhaps the ratio is not as important as some think.

It would be hard to think it less important that I think it is, since it is clearly useless when taken to extremes.

If nitrate is 5,000 ppm, does that mean the optimal phosphate is over 100 ppm?
If nitrate is 0.000005 ppm, does that mean the optimal phosphate is less than 0.0001 ppm?

Of course not. Both are ridiculous.

So why talk about ratios, as opposed to independently targeting both to "optimal"
ranges?

 

[TanksJB]

It would be hard to think it less important that I think it is, since it is clearly useless when taken to extremes.

If nitrate is 5,000 ppm, does that mean the optimal phosphate is over 100 ppm?
If nitrate is 0.000005 ppm, does that mean the optimal phosphate is less than 0.0001 ppm?

Of course not. Both are ridiculous.

So why talk about ratios, as opposed to independently targeting both to "optimal"
ranges?

Thanks Randy. I respect your judgment on things like this. So what, in your opinion is a good target for Nitrates and Phosphates, give or take, like in a range.

 

[DrZoidburg]

Did not read whole thread yet. I would consider some ratio important. Bacteria require phosphorus. If one messes that up it is like butterfly effect. Who knows what funny cyano, dino, pathogenic bacteria, or algae grow because of this.

 

[Hans-Werner]

So why talk about ratios, as opposed to independently targeting both to "optimal"
ranges?

... maybe because latest scientific findings and at least my own experiences with controlled nutrient supply suggest to do so?

Please see this article:

Hongwei Zhao et al:
It must be realized that both levels of nutrient
pollution and the stoichiometric ratios of C: N: P: Fe availabilities determine the ultimate effect of nutrients on
coral health. ...
Over the last decade, it became apparent that sensitivity to thermal
bleaching is largely determined by the stoichiometric ratio in which
the key nutrient ions ammonium, nitrate (jointly referred to as DIN –
Dissolved Inorganic Nitrogen), and phosphate (DIP – Dissolved Inorganic
Phosphorous) occur, rather than by absolute levels of nutrient
input. Under addition of DIN without a concurrent increase in DIP
(which is a typical characteristic of manipulative nutrient enrichment
– Fig. 1), phytoplankton cells multiply and consume DIP, resulting in
reduced phosphate availability (Haese et al. 2007). Phosphate is required
in corals in a specific ratio to nitrogen to maintain a stable
photosymbiosis (Ezzat et al. 2016a). ...
However, a meta-analysis
of nutrient-enrichment studies on corals showed that calcification
is differentially affected by nitrate and ammonium enrichment and
that phosphate is stimulating calcification (Shantz and Burkepile
2014). Phosphate enrichment is assumed to relieve DIC limitation
of calcification, because corals can incorporate CaHPO4 in their skeleton
instead of CaCO3 (Dunn et al. 2012). Nitrate uptake by the symbionts
reduces the translocation of photosynthetically acquired
carbon to the coral host, because the reduction of nitrate to ammonium
comes with a metabolic cost (Shantz and Burkepile 2014).
This implies that nitrate affects calcification through a reduction in
metabolic energy rather than competition for DIC, which is consistent
with the observation that moderate enrichment with ammonium
usually does not inhibit calcification (Fig. 5). ...
Experimental studies confirm the outcomes of the meta-analysis by
Shantz and Burkepile (2014). Enrichment of aquarium corals with nitrate
reduced calcification rates, whereas enrichment with ammonium
did not (Fernandes de BarrosMarangoni et al., 2020). Simultaneous enrichment
with nitrate and phosphate also resulted in a decrease in the
net calcification rate of individual and mixed coral communities
(Silbiger et al. 2018). Mixed coral communities changed from net calcification
to net dissolution undermoderate and high nutrient conditions.
This change was linked to a concurrent, nutrient-induced decrease in
the community P:R ratio, which caused the microenvironment around
the corals to become more acidic, thus reducing calcification (Silbiger
et al. 2018). Their study implies that negative effects of nitrate on calcification
are not alleviated by a concurrent addition of phosphate when
the nitrate concentration is too high. In contrast to nitrate enrichment,
ammonium enrichment at normal phosphorus levels promotes tissue
growth of both corals and symbionts, and thus positively affects coral
calcification (Table 1) (Shantz and Burkepile 2014; Guan et al. 2015;
Johnson and Carpenter 2018; Fernandes de Barros Marangoni et al.,
2020).

See also the dissertation and numerous publications of Andrew A. Shantz.

To point to natural vs. aquarium conditions doesn't always help because there are also scientific findings from aquariums and my own unscientific experimental findings.

 

[Lasse]

If nitrate is 5,000 ppm, does that mean the optimal phosphate is over 100 ppm?
If nitrate is 0.000005 ppm, does that mean the optimal phosphate is less than 0.0001 ppm?

Of cause not - but no one have talk about optimal ratio there both these nutrients is unlimited or limited. In the articles Hans Werner mentioned - the ration is important if it means that either of the main nutrients N and P become limited and it seems to be a threshold level of P - below that the N/P ratio is important. And yes - it has importance in aquarium there we often try to have P concentrations lower than this threshold.

@TanksJB Ratio of nitrogen and phosphorous in the literature often talk about N/P ratio not NO3/NH4 ratio in ppm. This is important as the often mentioned ratio 16/1 is about atoms of N and P. Or in other words NO3-N/PO4-P is 16/1. It mean 16 N atoms to one P atom. If we should convert this to a NO3/PO4 ratio in ppm - it will be 16*(14+3*16)/1*(31+4*16) -> 992/95 -> 10.44/1 as ppm NO3/ppm PO4. Note this is only an example - I´m not saying that the 16/1 N/P ratio is important for other things than N/P content in marine phytoplankton.

Sorry - the first way I wrote the latest paragraph looks like I try to educate Randy in a subject he know better than me. It was a response to TanksjB:s question in an earlier post.

Sincerely Lasse

 

[Randy Holmes-Farley]

... maybe because latest scientific findings and at least my own experiences with controlled nutrient supply suggest to do so?

Please see this article:

See also the dissertation and numerous publications of Andrew A. Shantz.

To point to natural vs. aquarium conditions doesn't always help because there are also scientific findings from aquariums and my own unscientific experimental findings.

I don't agree that ratios provide the best way to set target levels. That does not mean the ratio is never a useful concept to understand what might be happening in a reef tank (limiting nutrient, etc.), but I do not think it is EVER a desirable way to set reef aquarium target levels.

Of course there can be scenarios where either of N or P is too high or too low to be "optimal" for a reef aquarium". Thus, you have a sub-optimal ratio.

There are also scenarios where the right "ratio" with the wrong absolute values leads to very poor expected outcomes.

But is there ANY scenario where independently targeting N and P to optimal levels is suboptimal? I cannot conceive how that could be. What would that even mean?

Having optimal absolute values of N and P ALWAYS also has an "optimal" ratio.

Having the "optimal" ratio does not always mean you have "optimal" values.

 

[Randy Holmes-Farley]

... maybe because latest scientific findings and at least my own experiences with controlled nutrient supply suggest to do so?

Please see this article:

See also the dissertation and numerous publications of Andrew A. Shantz.

To point to natural vs. aquarium conditions doesn't always help because there are also scientific findings from aquariums and my own unscientific experimental findings.

Just to reiterate my point using a sentence from the paper you posted:

"Their study implies that negative effects of nitrate on calcification are not alleviated by a concurrent addition of phosphate when the nitrate concentration is too high."

That validates my point that ratios are NOT the best way to think on nutrients. Absolute values are the ticket.

 

[Hans-Werner]

"Their study implies that negative effects of nitrate on calcification are not alleviated by a concurrent addition of phosphate when the nitrate concentration is too high."

That validates my point that ratios are NOT the best way to think on nutrients. Absolute values are the ticket.

Ok, but what is the optimal or only a good concentration of nitrate, which is not too high? In the article N concentrations equal to nitrate in micrograms and not several milligrams are stated.

In my experience in reef tanks some nutrient(s) is or are always limiting. If it ain't nitrogen and phosphate it is some trace element(s).

When light is limiting corals should be quite dark and the tank also, in my opinion.

In my experience you can drive maybe any single nutrient into limitation. Then the question is, which one and at which ratio to other nutrients will become limiting.

 

[Randy Holmes-Farley]

Ok, but what is the optimal or only a good concentration of nitrate, which is not too high? In the article N concentrations equal to nitrate in micrograms and not several milligrams are stated.

In my experience in reef tanks some nutrient(s) is or are always limiting. If it ain't nitrogen and phosphate it is some trace element(s).

When light is limiting corals should be quite dark and the tank also, in my opinion.

In my experience you can drive maybe any single nutrient into limitation. Then the question is, which one and at which ratio to other nutrients will become limiting.

I certainly agree with everything you wrote, and understand that setting the optimal levels is not perfect, and may depend on the exact organisms present and the chemical forms of N and P present.

OTOH, I'm not convinced that, for an individual reefer trying to know what is the best, thinking about ratios makes that problem any easier.

 

[Hans-Werner]

may depend on the exact organisms present and the chemical forms of N and P present.

I agree. My impression is that different corals like different ratios or concentrations best. I am convinced this is one of the factors that determines the natural occurance or non-occurance of a species in a specific habitat. Upwelling, runoff or volcanic rocks may alter macro and micro nutrient supply to a specific habitat.